Zeolitic materials, both natural and synthetic, are known to have utility as sorbent materials and to have catalytic properties for various types of hydrocarbon conversion reactions. Certain zeolitic materials are ordered, porous crystalline metallosilicates having a definite crystalline structure as determined by X-ray diffraction, within which there are a large number of smaller cavities which may be interconnected by a number of still smaller channels or pores. These cavities and pores are uniform in size within a specific zeolitic material. Since the dimensions of these pores are such as to accept for sorption of molecules of certain dimensions while rejecting those of larger dimensions, these materials have come to be known as “molecular sieves” and are utilized in a variety of ways to take advantage of these properties.
Such molecular sieves, both natural and synthetic, include a wide variety of positive ion-containing crystalline silicates and substituted silicates, in which the silicon is partially or completely replaced by other tetravalent elements. These silicates can be described as a rigid three-dimensional framework of SiO4 tetrahedra and optionally tetrahedra of a trivalent element oxide, e.g., AlO4 and/or BO4, in which the tetrahedra are cross-linked by the sharing of oxygen atoms whereby the local ratio of the total trivalent element and silicon atoms to oxygen atoms is ˜1:˜2. The electrovalence of the tetrahedra containing the trivalent element is balanced by the inclusion in the crystal of a cation, for example, an alkali metal or an alkaline earth metal cation. This can be expressed wherein the ratio of the trivalent element, e.g., aluminum, to the number of various cations, such as Ca/2, Sr/2, Na, K or Li, is approximately equal to unity. One type of cation may be exchanged either entirely or partially with another type of cation utilizing ion exchange techniques in a conventional manner. By means of such cation exchange, it has been possible to vary the properties of a given silicate by suitable selection of the cation.
Prior art techniques have resulted in the formation of a great variety of synthetic zeolites. Many of these zeolites have come to be designated by letter or other convenient symbols, as illustrated by zeolite A (U.S. Pat. No. 2,882,243); zeolite X (U.S. Pat. No. 2,882,244); zeolite Y (U.S. Pat. No. 3,130,007); zeolite ZK-5 (U.S. Pat. No. 3,247,195); zeolite ZK-4 (U.S. Pat. No. 3,314,752); zeolite ZSM-5 (U.S. Pat. No. 3,702,886); zeolite ZSM-11 (U.S. Pat. No. 3,709,979); zeolite ZSM-12 (U.S. Pat. No. 3,832,449), zeolite ZSM-20 (U.S. Pat. No. 3,972,983); ZSM-35 (U.S. Pat. No. 4,016,245); zeolite ZSM-23 (U.S. Pat. No. 4,076,842); zeolite MCM-22 (U.S. Pat. No. 4,954,325); and zeolite MCM-35 (U.S. Pat. No. 4,981,663), to name merely a few.
There are currently over 200 known zeolitic framework structures recognized by the International Zeolite Association. There exists the need for new structures, having different properties than those of known materials, for improving the performance of many organic compound conversion and sorption processes. Each structure has unique pore, channel and cage dimensions, which gives its particular properties as described above. EMM-26 is a new synthetic crystalline material having a unique framework structure with a two-dimensional pore system defined by 10-membered rings of tetrahedrally coordinated atoms having pore dimensions of ˜6.3 Å (±˜0.4 Å)×˜3.2 Å (±˜0.3 Å). EMM-26 can have utility in organic compound conversion and/or sorption processes.